ISO/IEC 9126 Software engineering Product quality is an international standard for the evaluation of software quality
The quality model established in the first part of the standard, ISO/IEC 9126-1, classifies software quality in a structured set of characteristics and sub-characteristics as follows:
* Functionality – A set of attributes that bear on the existence of a set of functions and their specified properties. The functions are those that satisfy stated or implied needs.
* Reliability – A set of attributes that bear on the capability of software to maintain its level of performance under stated conditions for a stated period of time.
* Usability – A set of attributes that bear on the effort needed for use, and on the individual assessment of such use, by a stated or implied set of users.
* Efficiency – A set of attributes that bear on the relationship between the level of performance of the software and the amount of resources used, under stated conditions.
* Maintainability – A set of attributes that bear on the effort needed to make specified modifications.
* Portability – A set of attributes that bear on the ability of software to be transferred from one environment to another.